1 files changed, 41 insertions, 0 deletions
diff --git a/gcc/testsuite/gcc.target/msp430/pr87691.c b/gcc/testsuite/gcc.target/msp430/pr87691.c
new file mode 100644
index 00000000000..c00425d2452
--- /dev/null
+++ b/gcc/testsuite/gcc.target/msp430/pr87691.c
@@ -0,0 +1,41 @@
+/* PR 87691 - Test that a union containing __int20 and a float is not treated as
+   20-bits in size.  */
+
+/* { dg-do compile } */
+/* { dg-skip-if "no __int20 for mcpu=msp430" { *-*-* } { "-mcpu=msp430" } { "" } } */
+/* { dg-final { scan-assembler-not "MOVX.A" } } */
+
+/* To move a 20-bit value from memory (using indexed or indirect register
+   mode), onto the stack (also addressed using indexed or indirect register
+   mode), MOVX.A must be used. MOVA does not support these addressing modes.
+   Therefore, to check that the union is not manipulated as a 20-bit type,
+   test that no MOVX.A instructions are present in the assembly.
+
+   MOVA is used to fill/spill u.i, but if the union is treated as 20 bits in
+   size, MOVX.A would be used. No other __int20 operations are present
+   in the source, so there will be no valid uses of MOVX.A in the resulting
+   assembly.  */
+
+union U1
+{
+  float f;
+  __int20 i;
+};
+
+union U2
+{
+  __int20 i;
+  float f;
+};
+
+float foo1 (union U1 u)
+{
+  u.i += 42;
+  return u.f;
+}
+
+float foo2 (union U2 u)
+{
+  u.i += 42;
+  return u.f;
+}